1. Field of the Invention
The invention lies in the realm of mechanics and ballistics. More particularly, the invention discloses a shaped charge explosive yielding a 120.degree. shaped charge, particle dispersion, radially from the point of detonation, and further discloses an improved warhead cook-off capability to prevent an undesirable explosion/detonation of the warhead.
2. Description of the Prior Art
Anti-Radiation Missile (ARM) warhead designs are premised on the assumption that the missile they are employed in will not impact on a vulnerable region of the target. This is essentially the case as the aimpoint is on the transmitter antenna; however, an impact on the antenna usually will only degrade the performance of the radar. As a result such warheads are designed to produce significant levels of damage without actually impacting on the target. This is accomplished through the explosive dispersion of a large number of metallic fragments. In the design of ARM warheads, two basic factors must be taken into account. These factors are the probability of hitting the target, PH, and the probability of killing the target, PKH, given a hit by the fragmentation. The overall probability of killing the target, PK, is the product of these two factors. EQU PK=PH.times.PKH
Since no probability value can ever exceed 1, the system PK can never exceed either PH or PKH. Theses two factors, PH and PKH, are interrelated through the warhead design. The probability of a hit (PH) is a function of the miss distance which is controlled by the guidance system, the burst point location which is controlled by the fuze, and the number of fragments and their impact densities on intercepting the target which is controlled by the warhead design. The probability of kill (PKH), given a hit, is controlled by the placement and shielding of the components, i.e. the target, size of the fragments, and impact densities on intercepting the target. As can be seen, the impact densities are an important element in determining a target kill. This, however, results in conflicting requirements being placed on the warhead design, the need for high impact densities, for high PKH's, but large dispersion angles, for high PH's, which leads to low impact densities. Past warhead designs for ARM applications have usually employed a cylindrical shape with an ogival front end. When looked at in cross section, the warhead design appears as a series of stepped layers of fragmentation along the length with an explosive fill in the center. When the warhead is detonated in a static environment, the fragmentation, except for the ogive, is projected radially outward, the sections with the larger number of fragments being projected at a lower velocity than the sections with fewer fragments. When a missile with a sufficiently high terminal velocity is used with the warhead in that missile, this fragment pattern turns into an expanding cone of fragmentation due to the vector addition of missile and fragment ejection velocity. This design approach has certain limitations. First, it requires relatively high terminal missile velocities to achieve proper fragment dispersion. Second, because it is an expanding cone, it relies upon proper burst point control by the fuze so that the warhead does not detonate after it has passed the target. This requires a sophisticated fuze and/or a relatively small miss distance which requires more sophisticated guidance. More specifically, it requires that target location along the trajectory be known with respect to fuze and guidance systems. As a result very simple fuzing, such as fixed height of burst fuzes, cannot be readily used with this type of warhead.
Therefore, there exists a continuing need for a more effective warhead that can yield a greater probability of kill in near miss situations with less sophisticated fuze and guidance equipment, less missile terminal velocities, and a radially shaped charge having an expanding cone of projectiles to the rear (aft) as well as to the leading edge (fore) of the fly by missile.